Backgroud : To study the distribution of the polymorphism of apo E and angiotensin converting enzyme genotypes in type 2 diabetic patients and to evaluate possible association between the apo E genotypes and angiotensin converting enzyme genotypes and intima-media thickness of the common carotid artery. Methods : Study participants were 206 type 2 diabetic patients (112 men and 94 women), aged 18-81 years. HbA1C, albuminuria, and lipid status were assessed by standard laboratory techniques ; the apo E genotypes were assessed by modified amplification refractory mutation system of polymerase chain reaction technique and the angiotensin converting enzyme genotypes were assessed by multiplex polymerase chain reaction technique. The intima-media thickness was measured by high-resolution ultrasonography. Results : The apo E allele frequencies of patients were E2 11%, E3 72%, and E4 17%. Mean HDL-cholesterol was lower in E4 carrier (n=35) than E2 (n=148) and E3 (n=35) carrier. E2 carriers has less common carotid intima-media thickness than E3 and E4 carriers (p<0.05). The angiotensin converting enzyme genotypes were distributed as follows ; II 38%, ID 47%, DD 15%. The intima-media thickness value did not differ among patients with various genotypes. Multiple logistic regression analysis showed that only apo E polymorphism was determinant for the intima-media thickness. Conclusion : Our results suggested that apo E polymorphism was associated with carotid artery